Compression screw spike



July 28, 1936. H. s. CLARKE COMPRESSION SCREW SPIKE Filed May 12, 1954 INVENTOR. Herber? S. C/ar/(e.

ATTORNEY.-

Patented July 28, 1936 2,049,105 COMPRESSION SCREW SPIKE Herbert s. Clarke, Albany, N. Y., assignor to The Rails Company, New Haven,

ration of Connecticut Conn, a corpo- Application May 12, 1934, Serial No. 725,277

5 Claims.

This invention relates primarily to means for securing the tie plates of railroad tracks to the ties or other supports, independently of the rail.

Generally where the practice of fastening the tie plate to the rail independently of the rail fastening is used, a screw spike with a head design somewhat similar to that recommended by the A. R. E. A. has been used. This depends upon surface contact of the under side of the head against the tie plate and provides no takeup against wear. Moreover, in manufacturing it is not practical with the standard screw spike to have it fit the tie plate hole. Certain tolerances are unavoidable. The clearance may be minute to begin with but with constant use wear will increase the size of the hole and decrease the size of the neck of the spike, finally making it necessary to regauge track.

' Further, it is conceded that with present fastenings, more treated ties are destroyed by mechanical wear than by decay. Yet a great cause of failure is spike killing. This is not only mechanical damage to the wood fibre due to spikes but also decay in the interior of the tie which has its inception at the spike hole. Another cause of failure is mechanical abrasion due to loose tie plates.

The primary object of the present invention is to provide a compression type screw spike or tie plate screw adapted to fixedly attach a tie plate to a tie and provide take-up against wear.

A further object is to provide a compression screw spike or tie plate screw which will fit the hole in the tie plate, regardless of tolerance, and compress the plate into the tie; at the same time preventing lateral movement of the tie plate under traffic.

Another object of my invention is to provide a spike or screw of the type described adapted to plug the hole in the tie, sealing it against seepage of water.

With the foregoing and other objects in view, as will be apparent to those skilled in the art, my invention resides in the combination and arrangement of parts and in the details of construction as described in this specification and particularly pointed out in the appended claims. I intend no limitations other than those of the claims, it being understood that changes may be made within the scope of what is claimed without departing from the spirit of the invention. In the drawing I have illustrated a preferred form of device and the application thereof which will accomplish the objects recited and which embodies my invention. The drawing,

however, is furnished solely for illustrative purposes and I do not desire to be understood as limiting myself to the specific structure shown and described.

In the drawing:

Fig. 1 represents a screw spike according to this invention; Fig. 2 shows a modification with the tapered head as a separate thimble shown in section; Fig. 3 illustrates in part section the tie plate assembled on the tie, held in position by the compression screw spike of Fig. '1. Similar reference characters relate to similar parts in all the views.

In Fig. 1 a compression screw spike is shown Whose shank or stemis screw-threaded as at 6,

It will be observed (Fig. 3) that a tie plate 4 2 with an ordinary punched, drilled, or cast cylindrical hole may be mounted on a tie 3, the latter having been drilled or bored for a screw spike, as is usual. present invention may be driven into the tie, the tapered portion 9 enlarging the hole and preparing the way for the conical head 8 which passes through the tie plate hole or passage and A spike according to the follows the screw portion 9 into the tie, compressing the fibres of the tie at the top of the hole and sealing the,hole in the tie against seepage of Water.

At the same time, because of the conical shape,

the upper part of the head 8 contacts the side 40 walls of the hole in tie plate d in what is substantially a line contact, regardless of the tolerance left in the hole. 'The pressure of the conical head, as the spike is tightened, tends to force the tie plate into the tie, as well as to center the tie plate and prevent lateral movementin any direction. If the tie plate hole enlarges or the plate tends to loosen, the spike may be driven in further and remedy the condition, the tieplate holding portion 8 being of such length that when seated in the-.tie it will extend above the tie plate sufficiently t p take care of wear. that occasji'nal tightening of the spike will prevent any need arising for regauging of the track.

It is Iurther apparent that embedding the head 8 It is apparent,

'a conical head portion tapering in the wood of the tie provides greater strength against lateral action.

In the modification of Fig. 2, the conical headportion comprises a tapered thimble or col1ar I which may be hardened, adapted to slip over the threaded shank andfit on a cylindrical portion 2 of the spike under a head Ia provided by an enlargement below the polygonal part 1. The collar or thimble I, if desired, may be split longitudinally and provide a spring or resilient effect as the screw spike is driven into place. In solid form, as illustrated, the action of a screw spike made in accordance with Fig. 2 is similar in all respects to that of one illustratedin Fig. 3, except that a degree of hardness may be chosen for the thimble l without affecting the manufacture of the rest of the spike.

What I claim is:

1. In a tieplate fastening, the combination with a tie plate having a straight passage therethrough, of a compression screw spike having a threaded portion adapted to thread into a tie and from the end of the thread to the maximum diameter of the cone, the lower portion of said head being adapted and arranged to pass through said tie plate passage and follow the screw portion into a woodentie and compress the fibres of the tie, and the upper part of said head adapted and arranged for line contact with the side walls of said tie plate passage whereby to prevent side motion of said tie plate and to permit axial movement of said spike when said passage is enlarged, thereby permitting the maintenance of track gauge.

2. In a tieplate fastening, the combination with a tieplate having a straight passage therethrough of a compression screw said passage and provided with a threaded portion adapted to thread into a wooden tie, said portion being of constant diameter for the greater part of its length and increasing in diameter towards the upper end, and a conical head portion of continuous taper, slightly greater than the taper of the upper part of said threaded portion, from the end of the thread to the maximum diameter of said cone, whereby said conical head portion may follow said threaded portion into the tie and compress the fibres of the tie, said conical head portion having a limited area of contact with said tieplate and being of such length that when seated in the tie it will extend through and above the tie plate whereby to provide take-up means if the screw becomes loose, the area of contact and the increment of diameter of the spike being such that axial movement of the spike through the tieplate to maintain tightness oi the spike spike adapted to seat in in the tie is permitted by the rate of wear between the parts.

3. In a compression screw spike for tieplate fastening, a conical tieplate holding portion tapering from the end of the thread to the maxi-- mum diameter of said holding portion, whereby said portion may follow the threaded portion into a wooden tie and compress the fibres of the tie, said holding portion being of such length that when seated in the tie it will extend through and above the tie plate, the cone shape of said holding portion providing line contact with the tie plate whereby to provide take-up means if the screw becomes loose, the said line contact and the increment of diameter of the spike permitting axial movement of the spike through the tieplate to maintain tightness in the tie by reason of the rate of wear between the parts.

4. In a tieplate fastening, the combination with a wooden tie and a tieplate seated on said tie and having a passage therethrough, of a compression screw spike having a threaded portion adapted to thread into said tie and a conical tieplate engaging portion adapted and arranged for limited contact with the side walls of said tieplate passage and extending above said tieplate to provide an increased diameter whereby to take up wear by axial movement of said spike, the area of contact and the increment of diameter of the spike being such that wear will take place between the parts at a rate which will permit the spike to be maintained tight in the tie by axial movement of the spike through the tieplate.

5. A compression screw spike for tieplate fas-- tening in railroad construction, providing means for a limited area of contact with the tieplate whereby take-up is provided to permit wide tolerances in manufacture and to compensate for wear, said means comprising a tieplate-holding head portion of substantially conical shape adapted to extend with increased diameter above the tieplate and to project into the tieplate opening with decreased diameter merging smoothly into the threaded shank of said compression screw spike in order that the said conical holding portion may follow the threaded shank .into a wooden the tie whereby substantially to seal the spike hole in the tie, the area of contact and the increment of diameter of the spike being such that wear will take place between the parts at a rate which will permit the spike to be maintained tight in the tie by axial movement of the spike through the tieplate.

HERBERT S. CLARKE.

he below the tieplate and compress the fibres of 

